UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information. It's also known as GUID (Globally Unique Identifier). UUIDs are designed to be unique across space and time without requiring a central authority.

What are the differences between UUID versions?

UUID v1 is timestamp-based and sortable. UUID v3 uses MD5 hashing to create deterministic UUIDs from names. UUID v4 is randomly generated and most commonly used. UUID v5 is like v3 but uses SHA-1 for better security. Choose v4 for general use, v1 for time-series data, and v3/v5 for deterministic IDs.

What are UUID v3 and v5 used for?

UUID v3 and v5 create deterministic UUIDs from a namespace and name. They always generate the same UUID for the same inputs. This is useful for creating consistent IDs from known values like domain names, URLs, or other identifiers. v5 is preferred over v3 as it uses SHA-1 instead of MD5.

What is a namespace in UUID generation?

A namespace is a predefined UUID used as a base for v3/v5 generation. Common namespaces include DNS (for domain names) and URL (for web addresses). The namespace ensures UUIDs generated from the same name in different contexts remain unique.

Are the generated UUIDs truly unique?

UUID v4 has an extremely low probability of collision (duplicate). With 122 random bits, the chance of generating a duplicate is approximately 1 in 5.3 x 10^36. For practical purposes, they are considered unique.

Can I use these UUIDs in production?

Yes! The UUIDs generated by this tool use the same cryptographic random number generation as production systems. They are suitable for databases, APIs, and any production environment.

Is my data sent to a server?

No! All UUID generation happens locally in your browser using JavaScript. No data is sent to any server, ensuring complete privacy.

What format should I use?

The standard format with hyphens (8-4-4-4-12) is most common and widely supported. Use the format that matches your system's requirements.

How many UUIDs can I generate at once?

You can generate up to 100 UUIDs in a single bulk generation. For more, simply run the bulk generation multiple times.

Can I generate sequential UUIDs?

UUID v1 includes timestamp information, making them somewhat sequential and sortable by creation time. However, for true sequential IDs, consider using database auto-increment or other sequential ID generation methods.

Which UUID version should I use?

For most cases, use UUID v4 (random). Use v1 if you need time-based sorting. Use v3/v5 if you need to generate the same UUID from the same input consistently. v5 is preferred over v3 for better collision resistance.

UUID Generator

Generate unique identifiers (UUID/GUID) instantly. Support for UUID v1 (time-based), v3 (MD5), v4 (random), and v5 (SHA-1) with bulk generation.

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UUID Generator Tool Introduction

A powerful UUID Generator tool that creates universally unique identifiers (UUIDs) instantly. UUIDs are 128-bit numbers used to uniquely identify information in computer systems without requiring a central coordination authority.

Perfect for database keys, session identifiers, file names, API tokens, distributed systems, and any scenario requiring unique identifiers. Our tool supports all major UUID versions: v1 (timestamp-based), v3 (MD5 hash-based), v4 (random), and v5 (SHA-1 hash-based), with options for bulk generation.

Generate single or multiple UUIDs at once, copy them to clipboard with one click, and choose between uppercase, lowercase, or without hyphens formatting. For v3 and v5, create deterministic UUIDs from names and namespaces. All generation happens locally in your browser for maximum privacy and speed.

UUID Generator User Guide

Getting Started

Using the UUID Generator is simple and straightforward:

Basic Usage

Generate UUID: Click the "Generate" button to create a new UUID instantly.
Copy UUID: Click the copy button next to any UUID to copy it to your clipboard.
Bulk Generation: Enter the number of UUIDs you want to generate (1-100) and click "Generate Bulk".
Clear All: Remove all generated UUIDs to start fresh.

UUID Versions

UUID v1 (Time-based): Generated from timestamp and node ID. Sortable by creation time, useful for time-series data. Contains timestamp information making it partially predictable.
UUID v3 (MD5 hash): Generated from a namespace and name using MD5 hashing. Deterministic - same namespace and name always produce the same UUID. Useful for creating consistent IDs from known values.
UUID v4 (Random): Generated using cryptographically strong random numbers. Most commonly used version. Provides maximum unpredictability and security.
UUID v5 (SHA-1 hash): Similar to v3 but uses SHA-1 hashing instead of MD5. Preferred over v3 for better collision resistance. Also deterministic based on namespace and name.

Format Options

Standard: 8-4-4-4-12 format with hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000)
Uppercase: All letters in uppercase
Lowercase: All letters in lowercase (default)
No Hyphens: Remove all hyphens for compact format

Key Features

All UUID Versions: Support for v1 (time-based), v3 (MD5), v4 (random), and v5 (SHA-1)
Bulk Generation: Generate up to 100 UUIDs at once
Format Options: Uppercase, lowercase, with or without hyphens
Namespace Support: DNS and URL namespaces for v3/v5 generation
Deterministic UUIDs: Create consistent UUIDs from names using v3/v5
One-Click Copy: Copy individual UUIDs or all at once
Local Generation: All UUIDs generated in your browser for privacy
No Limits: Generate as many UUIDs as you need

When to Use Each Version

Use v1: When you need sortable IDs or want to track creation time
Use v3/v5: When you need deterministic UUIDs from names (e.g., generating UUIDs from domain names or URLs)
Use v4: For general purpose unique IDs where randomness is preferred (most common)

Frequently Asked Questions

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UUID Generator

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UUID Generator Tool Introduction

UUID Generator User Guide

Getting Started

Basic Usage

UUID Versions

Format Options

Key Features

When to Use Each Version

Frequently Asked Questions

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